On 17-Feb-09, at 9:35 PM, Scott Lawson wrote:
Toby Thain wrote:
On 17-Feb-09, at 3:01 PM, Scott Lawson wrote:
Hi All,
...
I have seen other people discussing power availability on other
threads
recently. If you
want it, you can have it. You just need the business case for it. I
don't buy the comments
on UPS unreliability.
Hi,
I remarked on it. FWIW, my experience is that commercial data
centres do not avoid 'unscheduled outages', no matter how many
steely-eyed assurances they give. It seems rather imprudent to
assume that power is never going to fail.
No matter how many diesel generators, rooftop tanks, or pebblebed
reactors you have, somebody is inevitably going to kick out a
plug... at least in most of the real world.
--Toby
Thats why you have two plugs if not more. I still don't buy your
argument. It comes down to procedural
issues on the site when it comes to people kicking plugs out.
Everything we have has dual power supplies,
feed from dual power rails, feed from separate switchboards,
through separate very large UPS's, backed by
generators, feed by two substations and then cloned to another data
center 3 km away. HA is all about
design. (I won't even comment about further up the stack than
electricity)
We have secure data centers with strict practices of work and
qualified staff following best practice for maintenance
and risk management around maintenance.
I am far, far more worried with someone with root access typing
'zpool destroy' than I am worried about the lights
going out in the data centers I designed that house hundreds and
hundreds of servers. ;) and no we don't have unplanned
outages. Not in a long time. Not all people that design data
centers know how to design power systems
for them. Sometimes the IT people don't convey their requirements
exactly enough to the electrical engineers. (I am
an electrical engineer who got sidetracked by SunOS around '91 and
never went back.)
Anyway we diverge I think. Maybe we can agree to disagree?
Not at all. You've convinced me. Your servers will never, ever lose
power unexpectedly.
--Toby
Back to discussions about disk caddies and
overpriced hardware.. slightly more closer to the topic at hand... ;)
...
--
____________________________________________________________________
___
Scott Lawson
Systems Architect
Manukau Institute of Technology
Information Communication Technology Services Private Bag 94006
Manukau
City Auckland New Zealand
Phone : +64 09 968 7611
Fax : +64 09 968 7641
Mobile : +64 27 568 7611
mailto:sc...@manukau.ac.nz
http://www.manukau.ac.nz
____________________________________________________________________
____
perl -e 'print
$i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);'
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--
______________________________________________________________________
_
Scott Lawson
Systems Architect
Manukau Institute of Technology
Information Communication Technology Services Private Bag 94006
Manukau
City Auckland New Zealand
Phone : +64 09 968 7611
Fax : +64 09 968 7641
Mobile : +64 27 568 7611
mailto:sc...@manukau.ac.nz
http://www.manukau.ac.nz
______________________________________________________________________
__
perl -e 'print
$i=pack(c5,(41*2),sqrt(7056),(unpack(c,H)-2),oct(115),10);'
______________________________________________________________________
__
_______________________________________________
zfs-discuss mailing list
zfs-discuss@opensolaris.org
http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
